Provided you both have hamachi and OC, you simply both sign onto hamachi, then the person hosting the session provides the client user with his hamachi IP address.

So the steps would be that you both log into hamachi, user A (the host) opens OC and goes to the networking properties box, and proceeds to modify the canvas area to suit the needs of all users involved, then stands by. Then use A provides user B with the IP provided by hamachi, user B then opens the networking box of OC and goes to the client tab and enters any relevant information as well as user A's IP address. Then user B simply presses connect, and viola, you're networked and able to draw.

That's one method, another is that we can schedule an open meet or you can contact them via IM. We can fit a max of 4 people in an OC session at a time, so we'd need to have multiple rooms if the demand is high enough. I'm willing to take the time to schedule these up and the like, people need to get in contact with me though.